Re: [PATCH v3 2/6] drm/sprd: add Unisoc's drm kms master

Daniel Vetter
2021-02-03T14:10:18Z

On Tue, Jan 05, 2021 at 09:46:03PM +0800, Kevin Tang wrote:
> Adds drm support for the Unisoc's display subsystem.
>
> This is drm kms driver, this driver provides support for the
> application framework in Android, Yocto and more.
>
> Application framework can access Unisoc's display internel
> peripherals through libdrm or libkms, it's test ok by modetest
> (DRM/KMS test tool) and Android HWComposer.
>
> Cc: Orson Zhai <orsonzhai@gmail.com>
> Cc: Chunyan Zhang <zhang.lyra@gmail.com>
> Signed-off-by: Kevin Tang <kevin.tang@unisoc.com>
> ---
> drivers/gpu/drm/Kconfig | 2 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/sprd/Kconfig | 12 +++
> drivers/gpu/drm/sprd/Makefile | 5 +
> drivers/gpu/drm/sprd/sprd_drm.c | 222 ++++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/sprd/sprd_drm.h | 16 +++
> 6 files changed, 258 insertions(+)
> create mode 100644 drivers/gpu/drm/sprd/Kconfig
> create mode 100644 drivers/gpu/drm/sprd/Makefile
> create mode 100644 drivers/gpu/drm/sprd/sprd_drm.c
> create mode 100644 drivers/gpu/drm/sprd/sprd_drm.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 147d61b..15b4e13 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -388,6 +388,8 @@ source "drivers/gpu/drm/tidss/Kconfig"
>
> source "drivers/gpu/drm/xlnx/Kconfig"
>
> +source "drivers/gpu/drm/sprd/Kconfig"
> +
> # Keep legacy drivers last
>
> menuconfig DRM_LEGACY
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 8156900..d3001e7 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -124,3 +124,4 @@ obj-$(CONFIG_DRM_ASPEED_GFX) += aspeed/
> obj-$(CONFIG_DRM_MCDE) += mcde/
> obj-$(CONFIG_DRM_TIDSS) += tidss/
> obj-y += xlnx/
> +obj-$(CONFIG_DRM_SPRD) += sprd/
> diff --git a/drivers/gpu/drm/sprd/Kconfig b/drivers/gpu/drm/sprd/Kconfig
> new file mode 100644
> index 0000000..6e80cc9
> --- /dev/null
> +++ b/drivers/gpu/drm/sprd/Kconfig
> @@ -0,0 +1,12 @@
> +config DRM_SPRD
> + tristate "DRM Support for Unisoc SoCs Platform"
> + depends on ARCH_SPRD || COMPILE_TEST
> + depends on DRM && OF
> + select DRM_KMS_HELPER
> + select DRM_GEM_CMA_HELPER
> + select DRM_KMS_CMA_HELPER
> + select DRM_MIPI_DSI
> + help
> + Choose this option if you have a Unisoc chipset.
> + If M is selected the module will be called sprd_drm.
> +
> diff --git a/drivers/gpu/drm/sprd/Makefile b/drivers/gpu/drm/sprd/Makefile
> new file mode 100644
> index 0000000..86d95d9
> --- /dev/null
> +++ b/drivers/gpu/drm/sprd/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +subdir-ccflags-y += -I$(srctree)/$(src)
> +
> +obj-y := sprd_drm.o
> diff --git a/drivers/gpu/drm/sprd/sprd_drm.c b/drivers/gpu/drm/sprd/sprd_drm.c
> new file mode 100644
> index 0000000..ec101de
> --- /dev/null
> +++ b/drivers/gpu/drm/sprd/sprd_drm.c
> @@ -0,0 +1,222 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 Unisoc Inc.
> + */
> +
> +#include <linux/component.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_graph.h>
> +#include <linux/of_platform.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_gem_cma_helper.h>
> +#include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_probe_helper.h>
> +#include <drm/drm_vblank.h>
> +
> +#include "sprd_drm.h"
> +
> +#define DRIVER_NAME "sprd"
> +#define DRIVER_DESC "Spreadtrum SoCs' DRM Driver"
> +#define DRIVER_DATE "20200201"
> +#define DRIVER_MAJOR 1
> +#define DRIVER_MINOR 0
> +
> +static const struct drm_mode_config_helper_funcs sprd_drm_mode_config_helper = {
> + .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
> +};
> +
> +static const struct drm_mode_config_funcs sprd_drm_mode_config_funcs = {
> + .fb_create = drm_gem_fb_create,
> + .atomic_check = drm_atomic_helper_check,
> + .atomic_commit = drm_atomic_helper_commit,
> +};
> +
> +static void sprd_drm_mode_config_init(struct drm_device *drm)
> +{
> + drm->mode_config.min_width = 0;
> + drm->mode_config.min_height = 0;
> + drm->mode_config.max_width = 8192;
> + drm->mode_config.max_height = 8192;
> + drm->mode_config.allow_fb_modifiers = true;
> +
> + drm->mode_config.funcs = &sprd_drm_mode_config_funcs;
> + drm->mode_config.helper_private = &sprd_drm_mode_config_helper;
> +}
> +
> +DEFINE_DRM_GEM_CMA_FOPS(sprd_drm_fops);
> +
> +static struct drm_driver sprd_drm_drv = {
> + .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
> + .fops = &sprd_drm_fops,
> +
> + /* GEM Operations */
> + DRM_GEM_CMA_DRIVER_OPS,
> +
> + .name = DRIVER_NAME,
> + .desc = DRIVER_DESC,
> + .date = DRIVER_DATE,
> + .major = DRIVER_MAJOR,
> + .minor = DRIVER_MINOR,
> +};
> +
> +static int sprd_drm_bind(struct device *dev)
> +{
> + struct drm_device *drm = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = drmm_mode_config_init(drm);
> + if (ret)
> + return ret;
> +
> + sprd_drm_mode_config_init(drm);
> +
> + /* bind and init sub drivers */
> + ret = component_bind_all(drm->dev, drm);
> + if (ret) {
> + drm_err(drm, "failed to bind all component.\n");
> + goto err_dc_cleanup;
> + }
> +
> + /* vblank init */
> + ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
> + if (ret) {
> + drm_err(drm, "failed to initialize vblank.\n");
> + goto err_unbind_all;
> + }
> + /* with irq_enabled = true, we can use the vblank feature. */
> + drm->irq_enabled = true;
> +
> + /* reset all the states of crtc/plane/encoder/connector */
> + drm_mode_config_reset(drm);
> +
> + /* init kms poll for handling hpd */
> + drm_kms_helper_poll_init(drm);
> +
> + ret = drm_dev_register(drm, 0);
> + if (ret < 0)
> + goto err_kms_helper_poll_fini;
> +
> + return 0;
> +
> +err_kms_helper_poll_fini:
> + drm_kms_helper_poll_fini(drm);
> +err_unbind_all:
> + component_unbind_all(drm->dev, drm);
> +err_dc_cleanup:
> + drm_mode_config_cleanup(drm);

This shouldn't be needed with drmm_mode_config_cleanup. I think the
trouble is that you have the drm_device setup split up between your probe
and your bind function, you need to move the call to drmm_mode_config_init
into you probe, or you move the devm_drm_dev_alloc and the entire setup
into your master_ops->bind function. I think the latter is the more usual
approach.

With that addressed Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> + return ret;
> +}
> +
> +static void sprd_drm_unbind(struct device *dev)
> +{
> + struct drm_device *drm = dev_get_drvdata(dev);
> +
> + drm_dev_unregister(drm);
> +
> + drm_kms_helper_poll_fini(drm);
> +
> + drm_mode_config_cleanup(drm);
> +
> + component_unbind_all(drm->dev, drm);
> +}
> +
> +static const struct component_master_ops drm_component_ops = {
> + .bind = sprd_drm_bind,
> + .unbind = sprd_drm_unbind,
> +};
> +
> +static int compare_of(struct device *dev, void *data)
> +{
> + return dev->of_node == data;
> +}
> +
> +static int sprd_drm_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct drm_device *drm;
> + struct sprd_drm *sprd;
> + int ret;
> +
> + sprd = devm_drm_dev_alloc(dev, &sprd_drm_drv, struct sprd_drm, drm);
> + if (IS_ERR(sprd))
> + return PTR_ERR(sprd);
> +
> + drm = &sprd->drm;
> +
> + ret = dma_set_mask_and_coherent(dev, ~0UL);
> + if (ret) {
> + drm_err(drm, "dma_set_mask_and_coherent failed (%d)\n", ret);
> + return ret;
> + }
> +
> + platform_set_drvdata(pdev, drm);
> +
> + return drm_of_component_probe(dev, compare_of, &drm_component_ops);
> +}
> +
> +static int sprd_drm_remove(struct platform_device *pdev)
> +{
> + component_master_del(&pdev->dev, &drm_component_ops);
> + return 0;
> +}
> +
> +static void sprd_drm_shutdown(struct platform_device *pdev)
> +{
> + struct drm_device *drm = platform_get_drvdata(pdev);
> +
> + if (!drm) {
> + drm_warn(drm, "drm device is not available, no shutdown\n");
> + return;
> + }
> +
> + drm_atomic_helper_shutdown(drm);
> +}
> +
> +static const struct of_device_id drm_match_table[] = {
> + { .compatible = "sprd,display-subsystem", },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, drm_match_table);
> +
> +static struct platform_driver sprd_drm_driver = {
> + .probe = sprd_drm_probe,
> + .remove = sprd_drm_remove,
> + .shutdown = sprd_drm_shutdown,
> + .driver = {
> + .name = "sprd-drm-drv",
> + .of_match_table = drm_match_table,
> + },
> +};
> +
> +static struct platform_driver *sprd_drm_drivers[] = {
> + &sprd_drm_driver,
> +};
> +
> +static int __init sprd_drm_init(void)
> +{
> + int ret;
> +
> + ret = platform_register_drivers(sprd_drm_drivers,
> + ARRAY_SIZE(sprd_drm_drivers));
> + return ret;
> +}
> +
> +static void __exit sprd_drm_exit(void)
> +{
> + platform_unregister_drivers(sprd_drm_drivers,
> + ARRAY_SIZE(sprd_drm_drivers));
> +}
> +
> +module_init(sprd_drm_init);
> +module_exit(sprd_drm_exit);
> +
> +MODULE_AUTHOR("Leon He <leon.he@unisoc.com>");
> +MODULE_AUTHOR("Kevin Tang <kevin.tang@unisoc.com>");
> +MODULE_DESCRIPTION("Unisoc DRM KMS Master Driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/sprd/sprd_drm.h b/drivers/gpu/drm/sprd/sprd_drm.h
> new file mode 100644
> index 0000000..9781fd5
> --- /dev/null
> +++ b/drivers/gpu/drm/sprd/sprd_drm.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020 Unisoc Inc.
> + */
> +
> +#ifndef _SPRD_DRM_H_
> +#define _SPRD_DRM_H_
> +
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_print.h>
> +
> +struct sprd_drm {
> + struct drm_device drm;
> +};
> +
> +#endif /* _SPRD_DRM_H_ */
> --
> 2.7.4
>

--
Daniel Vetter
Software Engineer, Intel Corporation